From a six metre steel rod heated up to 1200°C to an elegant and precise golf club ground by eye and hand&comma; our forging process guarantees that the metals natural grain is preserved in every step of the process&period;

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The Grain Flow Forging process was patented in 1998 – to create a precise iron head through multiple forging stages from a single billet of steel&period; Begin exploring what makes Grain Flow Forging a unique process&mldr;

Cast Head

Forged Head

ONE PIECE & MULTI&dash;PIECE CONSTRUCTION

One piece Grain Flow ForgingNeck and head are forged from the same single billet of steel&comma; ensuring continuous grain through the head&period;

Competitor forged iron with welded neckUnlike a Mizuno Grain Flow Forged iron the iron is made with two parts – with no continuous grain through the head&period;

Sound Test

Click the heads below to hear the difference between cast and forged club heads

Watch the video to hear the difference between cast and forged club heads

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Raw Cast Iron

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Polished cast iron

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Grain Flow Forged iron

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PRO MT & PRO VS

The first iron models produced through this refined process were the Pro MT and Mizuno Pro VS&period;

Mizuno Pro TN&dash;87 &lpar;1986&dash;1988&rpar;

Each head within Mizuno's incredible TN&dash;87 was individually shaped by leading tour player Tommy Nakajima&period;

Mizuno Pro TN&dash;87 (1986&dash;1988)

Each head within Mizuno's incredible TN&dash;87 was individually shaped by leading tour player Tommy Nakajima&period;

Mizuno Pro TN-87 (1986&dash;1988)

Each head within Mizuno's incredible TN&dash;87 was individually shaped by leading tour player Tommy Nakajima&period;

Materials

Crucial to the calibre and feedback of Mizuno clubs is the quality of materials selected for their forging&mldr;

Dedicated research into continuously improving our golf clubs led to our progression from 1025 Mild Carbon Steel to 1025E Pure Select&comma; as well as the revolutionary introduction of Boron&period;

1025E PURE SELECT MILD CARBON

The steel behind Mizuno's softest feeling irons&period; Used in our one piece irons for higher level players seeking the ultimate in precision and feedback&period; 1025 is used for its balance of strength&comma; bend&dash;ability and feel&period; The evolution to 1025E reduces unnecessary elements that occur during the forging process – phosphorus and sulphur&period;

Boron Infused Steel

Introduced in 2014 to combine the precision of a forged iron with the ball speed of a distance iron&period; Widely used in other industries&comma; the smallest trace of boron to the steel mix increases its strength during manufacture&period; Allowing Mizuno to create more complex one piece Grain Flow Forged irons like the MP&dash;25&comma; for a balance of feel&comma; precision and increased ball speeds&period;

Boron steel vs 1025E Pure Select Mild Carbon steel

A simple bladed iron like MP&dash;5 would have identical feel and performance from either a Boron infused or mild carbon steel billet&period; The Boron is only impactful when a more complex head design is required&period; Post manufacture both materials behave near identically&period;

In 1968, Mizuno moved the production of its forged irons to the Chuo plant in Hiroshima – on the west coast of Japan&period;

Still made in the same exclusive plant today, the partnership has allowed Mizuno to evolve and perfect its forging expertise over many years&period;

Step 1

Uncut Japanese steel rods are delivered into the forging plant – ready to be sheared into single 10 inch billets for every Grain Flow Forged iron&period;

The six&dash;metre steel rod are sheared into 10in length&period;

The raw steel rods are abrasion cleaned of any surface weathering prior to heating&period;

Buffered billets are ready for heating and bending process&period;

Step 2

Each Billet gets heated to 1200°C before being stretched and bent to the angle that will roughly form the head and hosel&period;

The bending stage ensures that the hosel and clubhead are forged from a single billet – to ensure a perfect grain flow throughout&period;

Step 3

primary forging stage

The bent billet is placed onto a forging mould and hit four times by a 1&comma;000&dash;ton hammer press to tightly align grains in the metal&period;

To control the thickness and weight of each clubhead&comma; the hammer operator uses a foot pedal – the process requires Chuo's most experienced staff&period;

The operators will work for 3 years before allowed onto the Mizuno hammers&period; Once on the hammers&comma; they work 5 more years under the watch of a master operator until they can work alone&period;

Every head in each model &lpar;both A and B headweights&rpar; has its own forging master mould for that specific set of clubs&period;

Step 4

Cookie cutter roughly trims off the excess metal from the cooled heads&comma; known as the flash&mldr;

Cookie cutter roughly trims off the excess metal from the cooled heads&comma; known as the flash&mldr;

&mldr;before being reheated for the precision forging stage&period;

&mldr;before being reheated for the precision forging stage&period;

Step 5

Precision Forging Stage

Each clubhead is reheated and pressure squeezed to create precise head shape before trimming&period;

With each stage of precision forging the billet is looking more and more like a useable golf club&period;

30 pairs of hands and eyes ensure each forged irons quality&period;

Until ready for grinding and plating&period;

Step 6

PLATING & GRINDING

Final Grain Flow Forged head ready for stamping&comma; polishing&comma; plating and assembly&period;

THE FINISHED ARTICLE

After plating the finished clubs are then shipped to their assembly plants ready to be custom assembled&period;

With our combination of market leading R&D&comma; cutting&dash;edge technology and stunning craftsmanship&comma; Mizuno can proudly say that we believe we produce some of the best irons in the world&period; Each and every club is produced with the user in focus&period;